A new study of mice suggests bacteria may help to cause anxiety and depression in overweight people.

The research raises questions about whether changing organisms living inside our bodies or changes in diet could help treat these conditions.

A 2017 study found that one-third of the world's population is overweight or considered obese.

When people become obese, this changes the processes by which the body uses food to make energy, build tissue and remove waste material. Left untreated, these changes can lead to diabetes.

Diabetes is a serious condition. It affects how your body uses blood sugar. Obese people also have higher rates of anxiety and depression than other individuals.

Ronald Kahn studies diabetes at Harvard Medical School in Massachusetts. He says researchers have wondered if people suffer from depression because they are obese or because of their metabolism.

"And we asked the question, 'Maybe the metabolic link is at least partly fueled by the microbiome,'" Kahn said.

The microbiome is the community of bacteria, fungi and other microorganisms living in your stomach. It changes with your diet. And Kahn says those changes may affect both body and mind.

To test the theory, he and his research team fed mice a high-fat diet and studied their behavior as the animals became obese.

In one test, they put mice in a box divided into a darkened area on one side and a light area on the other side. They found that the more nervous, anxious mice liked to spend time on the dark side.

"And a mouse on a high fat diet will spend more time in the dark than a mouse on a normal... diet will. So, they have more sign of anxiety," Khan said.

The anxiety went away when the mice were given antibiotic drugs.

The researchers said this suggests that the bacteria were helping make the mice nervous.

The researchers then wanted to see if they could produce the same effect by giving the same bacteria to animals raised in a bacteria-free environment, with no microbes of their own.

They found that it did. Microbes from obese mice made the bacteria-free mice anxious. Microbes from obese mice given antibiotics did not.

"It was actually quite a surprise," Khan said. "Even though we had seen some effects on metabolism in the rest of the body, I was very surprised how dramatic and how clear the effects were also on the brain and on behavior."

A?report?on the study appears in the journal?Molecular?Psychiatry.

Kahn noted, however, that the new study does not mean antibiotics are the cure for depression. The drug kills both good and bad microbes. Also, drug misuse is making these powerful medicines less effective.

Another important point, he said, is that what happens in mice does not necessarily happen in humans, or it may only happen for some people.

Gregory Simon is a mental health specialist at the Kaiser Permanente Washington Heath Research Institute. He said that it is also important to remember there is much more going on with people than just their microbes.

"The difficulty is, both of these things, depression and obesity, are complicated things that have multiple, multiple factors influencing them," Simon said.

He says genetics, environment, social influences and our microbes all help shape people and their behavior.

I'm Phil Dierking.

重點(diǎn)解析

1.lead to?導(dǎo)致

A lack of prudence may?lead to?financial problems.

不夠謹(jǐn)慎可能會(huì)導(dǎo)致財(cái)政上出現(xiàn)問題。

2.waste material?廢料；廢物

We should make use of the?waste material?and reduce the cost of production.

我們要廢物利用，降低成本。

3.mental health?心理健康

Poor housing and family stress can affect both physical and?mental health.

住房條件差、家庭壓力大會(huì)影響身心兩方面的健康。

4.Even though?即使

Even though?I'm quite a reserved person, I like meeting people.

我雖然性格極為內(nèi)斂，但喜歡和人接觸。

5.In one test, they put mice in a box divided into a darkened area on one side and a light area on the other side.

put?into?放進(jìn)

They had asked Hong Kong for permission to?put into?port there.

他們請(qǐng)求香港允許他們?cè)谀抢锶敫弁Ａ簟?/p>

The difference between successful and unsuccessful people is that successful people?put into?practice the things they learn

成功者與失敗者的區(qū)別在于成功者能夠?qū)W以致用。

6.It affects how your body uses?blood sugar.

blood sugar?血糖

Hunger is the body's signal that levels of?blood sugar?are too low.

饑餓感是身體發(fā)出的信號(hào)，表示血糖水平太低。

If you skip breakfast, your?blood sugar?level will drop and you will probably feel light-headed.

如果不吃早餐，血糖含量就會(huì)降低，你很可能會(huì)覺得暈眩。

參考譯文

研究表明：細(xì)菌可能會(huì)導(dǎo)致緊張和沮喪

一項(xiàng)針對(duì)老鼠的新研究表明，細(xì)菌可能會(huì)讓超重人群焦慮和抑郁。

該研究提出了這樣的問題——改變體內(nèi)的微生物或改變飲食是否有助于治療（緊張或抑郁）等疾病。

2017年的一項(xiàng)研究發(fā)現(xiàn)，全球三分之一的人口超重或被認(rèn)為肥胖。

當(dāng)人體超重時(shí)，會(huì)改變身體將食物轉(zhuǎn)化為能量、增加組織以及排泄體內(nèi)廢物的流程。如果不加以治療，這些變化可能會(huì)導(dǎo)致糖尿病。

糖尿病是一種嚴(yán)重的疾病，會(huì)影響人體利用血糖的方式。肥胖者也比正常人更容易產(chǎn)生焦慮和抑郁。

羅納德·卡恩（Ronald Kahn）在馬薩諸塞州的哈佛醫(yī)學(xué)院研究糖尿病。他說(shuō)，研究人員猜想，人們是否會(huì)因?yàn)樯眢w肥胖或新陳代謝患上抑郁癥。

卡恩說(shuō)：“我們提出了這樣一個(gè)問題‘也許代謝環(huán)節(jié)至少部分受到了微生物菌群的影響’?！?/p>

微生物菌群是指腸胃中的細(xì)菌、真菌及其它微生物群。它會(huì)隨著你的飲食發(fā)生變化?？ǘ髡f(shuō)，這些變化可能會(huì)影響到身體和精神。

為了驗(yàn)證這一理論，他與自己的研究團(tuán)隊(duì)喂老鼠吃高脂肪食物，研究老鼠增肥時(shí)的行為。

在一次試驗(yàn)中，他們把老鼠放進(jìn)一半明亮、一半黑暗的盒子內(nèi)。他們發(fā)現(xiàn)，越緊張、焦慮的老鼠越喜歡呆在黑暗區(qū)域。

卡恩說(shuō)到：“高脂飲食的老鼠比正常飲食的老鼠呆在黑暗區(qū)域的時(shí)間更久。因此，它們出現(xiàn)焦慮的跡象更多?！?/p>

當(dāng)給老鼠服用抗生素藥物后，它們的焦慮感消失了。

研究人員表示，這表明細(xì)菌會(huì)使老鼠感到緊張。

隨后，研究人員猜想，將同樣的細(xì)菌植入到在無(wú)菌環(huán)境中培養(yǎng)本身并無(wú)微生物的動(dòng)物身上，能否產(chǎn)生同樣的效果。

他們發(fā)現(xiàn)確實(shí)如此。肥胖小鼠體內(nèi)的微生物會(huì)讓無(wú)菌老鼠感到焦慮。而注射過(guò)抗生素的肥胖小鼠的微生物卻不會(huì)（讓無(wú)菌老鼠感到焦慮）。

卡恩表示：“這一發(fā)現(xiàn)十分驚人。盡管我們?cè)谏眢w的其它部位看到了一些細(xì)菌對(duì)新陳代謝的影響，但令我吃驚的是，它對(duì)大腦和行為的影響也如此地顯著和清晰。”

這項(xiàng)研究的報(bào)告發(fā)表在《分子精神病學(xué)》雜志上。

然而，卡恩指出，新研究并不意味著抗生素可以治療抑郁癥?？股貢?huì)同時(shí)殺死有益和有害的微生物。而且，濫用藥物會(huì)導(dǎo)致這些強(qiáng)效藥的藥效降低。

他指出，還有一個(gè)問題要注意，老鼠的實(shí)驗(yàn)效果不一定適用于人類，或者只適用于某些人群。

格雷戈里·西蒙（Gregory Simon）是凱薩醫(yī)療機(jī)構(gòu)華盛頓健康研究所的精神健康專家。他說(shuō)，影響人類的因素很多，不僅僅是微生物，這一點(diǎn)也要謹(jǐn)記在心。

西蒙說(shuō)：“關(guān)鍵在于，抑郁癥和肥胖癥的成因十分復(fù)雜，他們受到很多種因素的影響。”

他說(shuō)，基因、環(huán)境、社會(huì)影響以及自身的微生物都會(huì)對(duì)塑造一個(gè)人和其行為產(chǎn)生影響。

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